The invention concerns a process for the permanent joining of threadlike or small ribbonlike elements to a flat substrate by means of an adhesive, as well as the use of this process for producing frilled sections of a film sheet or a foil course (strip).
It is generally known, and in particular for the production of diaper pants or disposable diapers, e.g. from DE-OS No. 34 47 442 and DE-PS No. 33 47 294, that when joining threadlike or small ribbonlike elastic elements with a flat substrate either to provide the surfaces of two parts to be joined with an adhesive and to press these surfaces provided with adhesive together, or to provide only the threadlike or small ribbonlike elements, or only the flat substrate with the adhesive, whereafter both parts are pressed together. These types of processes, in particular in the case of producing bulk articles, are both time consuming and expensive for apparatus. For example, the adhesive must be applied with application rollers or nozzles to at least one of the elements to be glued together and this latter then pressed. Gluing threadlike elements to the flat substrate brings up problems, in particular in the case of the threadlike elements when dealing with an elastic thread held under tension, as is, for example, used for frilling tightly closing, flat structures made of plastic and/or irregular fiber fleece, as is required in the hygienic area, e.g. for a diaper or diaper pants, also in the case of work clothes, in order to enable a better fitting or snugging capability; similar problems arise when producing operating room caps and face masks used in the surgical field, and in the case of numerous other articles in the hygienic and medical area of application.
The invention provides a new process for the permanent joining of threadlike or small ribbonlike elastic elements to a flat substrate by means of an adhesive that is capable of being used without great expense, and that is suited for a permanent joining, in particular of threadlike elastic elements to a flat substrate and, actually, preferentially with an elastic thread under tension that is to be joined with a plastic film or foil underlay.
The invention also provides the use of this new joining process for elastic threads for producing desired sections of film sheet or foil course with stretchable threadlike or small ribbonlike elements located in the respective edge region between a film, or a foil and a covering layer, an absorbent inlay disposed therebetween, and with a section of fleece covering the absorbent inlay.